Collaborative Research: Integrating Petrochronology, Magma Dynamics, and Volcanic Unrest at the Three Sisters Volcanic Complex

合作研究：综合岩石年代学、岩浆动力学和三姐妹火山群的火山动荡

• 批准号: 1941062
• 负责人: Helene Le Mevel
• 金额: $ 1.92万
• 依托单位: Carnegie Institution of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-02-15 至 2025-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1941062&HistoricalAwards=false
• 关键词: Collaborative; Research; Integrating; Petrochronology; Magma

Volcanic eruptions have to potential to threaten agriculture, infrastructure, aviation, and human life at local to global scales. These events represent the intersection of geologic processes that proceed over thousands to millions of years and destabilization of the volcanic reservoir which may occur rapidly over only days to years. These processes may be interrogated through retrospective geologic studies of past eruptions and geophysical monitoring, respectively. This project is focused on integrating these approaches at the Three Sisters Volcanic Complex, a “very high threat potential” volcanic system located in the western United States. The goals are to elucidate hazards specific to the Three Sisters through the investigation of recent eruptions and volcanic unrest and produce new conceptual and quantitative models that can be applied to understand the hazards and improve eruption forecasting for active volcanoes globally. The results of this project will be disseminated to the general public through animation and videos published on-line and a self-guided geology hiking guide made available to the many recreational visitors to the Three Sister’s Wilderness Area.Linking the processes that catalyze the growth, evolution, destabilization, and eruption of magma reservoirs to their expression as observable unrest represents an important scientific frontier that requires inter-disciplinary collaborations across the geosciences. Parallel advances in geophysics, petrochronology, and numerical modeling have made substantial contributions to the understanding of magma reservoir processes. Yet, these methods remain poorly integrated. The unusual confluence of frequent late Pleistocene to late Holocene eruptions, which range in composition from basaltic andesite to rhyolite, with modern volcanic unrest make the Three Sisters a prime natural laboratory at which to pursue this integrated approach. This project will produce new crystal-scale petrochronologic data for lavas and associated explosive products erupted from the Three Sisters Volcanic Complex, central Oregon Cascades, during the last ca. 50,000 yr. These data will inform interpretations of: 1) the petrogenesis of the rhyolite and dacite lavas erupted at the Three Sisters and if there is a genetic relationship between these rock types; 2) the longevity and physical integration of the magma reservoir(s) that produced the late Pleistocene flare-up of intermediate and silicic volcanism; and 3) the nature and tempo of the processes that preceded, and potentially triggered, these eruptions. In parallel, a high-resolution Bouguer gravity survey will be conducted to constrain the physical structure of the modern magma reservoir. These new geochemical and geophysical data will be integrated with the existing geodetic observations of recent uplift in coupled models of magma dynamics and crustal deformation. Accordingly, these observations and models will quantitatively test if recent unrest at Three Sisters reflects similar processes to those associated with the late-Pleistocene volcanism.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

火山爆发有可能在局部到全球范围内威胁农业，基础设施，航空和人类生活。这些事件代表了数千年至数百万年的地质过程和可能在几天至几年内迅速发生的火山储层不稳定的交叉。这些过程可以通过对过去喷发的回顾性地质研究和地球物理监测来分别进行询问。该项目的重点是在三个姐妹篇火山复合体-一个位于美国西部的“潜在威胁非常高”的火山系统-综合采用这些方法。其目标是通过调查最近的火山爆发和火山动荡，阐明“三姐妹姐妹篇”特有的危险，并提出新的概念和定量模型，可用于了解危险，改进全球活火山的火山爆发预测。该项目的成果将通过在线发布的动画和视频向公众传播，并向三姐妹荒野地区的许多休闲游客提供自助地质徒步旅行指南。和岩浆库的喷发，以其可观察到的动荡的表达代表了一个重要的科学前沿，需要相互-地球科学领域的学科合作。在地球物理学、岩石年代学和数值模拟方面的平行进展对岩浆储层过程的理解做出了实质性贡献。然而，这些方法仍然缺乏整合。频繁的晚更新世到晚全新世火山喷发（其成分从玄武安山岩到流纹岩不等）与现代火山动荡的不寻常汇合，使三姐妹篇成为追求这种综合方法的主要天然实验室。该项目将产生新的晶体规模的熔岩和相关的爆炸产物喷发的三个姐妹篇火山复合体，中央俄勒冈州瀑布，在过去的一年中，岩石年代学数据。五万年这些数据将为以下解释提供信息：1）三姐妹篇火山喷发的流纹岩和英安岩熔岩的岩石成因，以及这些岩石类型之间是否存在成因关系; 2）产生晚更新世中期和中期火山活动爆发的岩浆库的寿命和物理整合;以及3）这些爆发之前和潜在触发这些爆发的过程的性质和克里思。与此同时，将进行高分辨率布格重力测量，以限制现代岩浆库的物理结构。这些新的地球化学和地球物理数据将与现有的最近隆起的大地测量观测结果结合在一起，形成岩浆动力学和地壳变形的耦合模型。因此，这些观测和模型将定量测试，如果最近在三个姐妹篇动荡反映了类似的过程，与晚更新世火山活动。这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。